<?php

    /**
     * PHPExcel_CachedObjectStorage_Wincache
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_CachedObjectStorage
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    class PHPExcel_CachedObjectStorage_Wincache extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache {
        /**
         * Prefix used to uniquely identify cache data for this worksheet
         * @var string
         */
        private $cachePrefix = null;
        /**
         * Cache timeout
         * @var integer
         */
        private $cacheTime = 600;

        /**
         * Initialise this new cell collection
         * @param    PHPExcel_Worksheet $parent The worksheet for this cell collection
         * @param                       array   of mixed        $arguments    Additional initialisation arguments
         */
        public function __construct(PHPExcel_Worksheet $parent, $arguments) {
            $cacheTime = (isset($arguments['cacheTime'])) ? $arguments['cacheTime'] : 600;
            if (is_null($this->cachePrefix)) {
                $baseUnique        = $this->getUniqueID();
                $this->cachePrefix = substr(md5($baseUnique), 0, 8) . '.';
                $this->cacheTime   = $cacheTime;
                parent::__construct($parent);
            }
        }

        /**
         * Identify whether the caching method is currently available
         * Some methods are dependent on the availability of certain extensions being enabled in the PHP build
         * @return    boolean
         */
        public static function cacheMethodIsAvailable() {
            if (!function_exists('wincache_ucache_add')) {
                return false;
            }
            return true;
        }

        /**
         * Add or Update a cell in cache identified by coordinate address
         * @param    string        $pCoord Coordinate address of the cell to update
         * @param    PHPExcel_Cell $cell   Cell to update
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function addCacheData($pCoord, PHPExcel_Cell $cell) {
            if (($pCoord !== $this->currentObjectID) && ($this->currentObjectID !== null)) {
                $this->storeData();
            }
            $this->cellCache[$pCoord] = true;
            $this->currentObjectID    = $pCoord;
            $this->currentObject      = $cell;
            $this->currentCellIsDirty = true;
            return $cell;
        }

        /**
         * Store cell data in cache for the current cell object if it's "dirty",
         *     and the 'nullify' the current cell object
         * @return    void
         * @throws    PHPExcel_Exception
         */
        protected function storeData() {
            if ($this->currentCellIsDirty && !empty($this->currentObjectID)) {
                $this->currentObject->detach();
                $obj = serialize($this->currentObject);
                if (wincache_ucache_exists($this->cachePrefix . $this->currentObjectID . '.cache')) {
                    if (!wincache_ucache_set($this->cachePrefix . $this->currentObjectID . '.cache', $obj, $this->cacheTime)) {
                        $this->__destruct();
                        throw new PHPExcel_Exception('Failed to store cell ' . $this->currentObjectID . ' in WinCache');
                    }
                } else {
                    if (!wincache_ucache_add($this->cachePrefix . $this->currentObjectID . '.cache', $obj, $this->cacheTime)) {
                        $this->__destruct();
                        throw new PHPExcel_Exception('Failed to store cell ' . $this->currentObjectID . ' in WinCache');
                    }
                }
                $this->currentCellIsDirty = false;
            }
            $this->currentObjectID = $this->currentObject = null;
        }

        /**
         * Destroy this cell collection
         */
        public function __destruct() {
            $cacheList = $this->getCellList();
            foreach ($cacheList as $cellID) {
                wincache_ucache_delete($this->cachePrefix . $cellID . '.cache');
            }
        }

        /**
         * Get a list of all cell addresses currently held in cache
         * @return  string[]
         */
        public function getCellList() {
            if ($this->currentObjectID !== null) {
                $this->storeData();
            }
            return parent::getCellList();
        }

        /**
         * Is a value set in the current PHPExcel_CachedObjectStorage_ICache for an indexed cell?
         * @param    string $pCoord Coordinate address of the cell to check
         * @return    boolean
         */
        public function isDataSet($pCoord) {
            //    Check if the requested entry is the current object, or exists in the cache
            if (parent::isDataSet($pCoord)) {
                if ($this->currentObjectID == $pCoord) {
                    return true;
                }
                //    Check if the requested entry still exists in cache
                $success = wincache_ucache_exists($this->cachePrefix . $pCoord . '.cache');
                if ($success === false) {
                    //    Entry no longer exists in Wincache, so clear it from the cache array
                    parent::deleteCacheData($pCoord);
                    throw new PHPExcel_Exception('Cell entry ' . $pCoord . ' no longer exists in WinCache');
                }
                return true;
            }
            return false;
        }

        /**
         * Get cell at a specific coordinate
         * @param    string $pCoord Coordinate of the cell
         * @throws    PHPExcel_Exception
         * @return    PHPExcel_Cell    Cell that was found, or null if not found
         */
        public function getCacheData($pCoord) {
            if ($pCoord === $this->currentObjectID) {
                return $this->currentObject;
            }
            $this->storeData();
            //    Check if the entry that has been requested actually exists
            $obj = null;
            if (parent::isDataSet($pCoord)) {
                $success = false;
                $obj     = wincache_ucache_get($this->cachePrefix . $pCoord . '.cache', $success);
                if ($success === false) {
                    //    Entry no longer exists in WinCache, so clear it from the cache array
                    parent::deleteCacheData($pCoord);
                    throw new PHPExcel_Exception('Cell entry ' . $pCoord . ' no longer exists in WinCache');
                }
            } else {
                //    Return null if requested entry doesn't exist in cache
                return null;
            }
            //    Set current entry to the requested entry
            $this->currentObjectID = $pCoord;
            $this->currentObject   = unserialize($obj);
            //    Re-attach this as the cell's parent
            $this->currentObject->attach($this);
            //    Return requested entry
            return $this->currentObject;
        }

        /**
         * Delete a cell in cache identified by coordinate address
         * @param    string $pCoord Coordinate address of the cell to delete
         * @throws    PHPExcel_Exception
         */
        public function deleteCacheData($pCoord) {
            //    Delete the entry from Wincache
            wincache_ucache_delete($this->cachePrefix . $pCoord . '.cache');
            //    Delete the entry from our cell address array
            parent::deleteCacheData($pCoord);
        }

        /**
         * Clone the cell collection
         * @param    PHPExcel_Worksheet $parent The new worksheet
         * @return    void
         */
        public function copyCellCollection(PHPExcel_Worksheet $parent) {
            parent::copyCellCollection($parent);
            //    Get a new id for the new file name
            $baseUnique     = $this->getUniqueID();
            $newCachePrefix = substr(md5($baseUnique), 0, 8) . '.';
            $cacheList      = $this->getCellList();
            foreach ($cacheList as $cellID) {
                if ($cellID != $this->currentObjectID) {
                    $success = false;
                    $obj     = wincache_ucache_get($this->cachePrefix . $cellID . '.cache', $success);
                    if ($success === false) {
                        //    Entry no longer exists in WinCache, so clear it from the cache array
                        parent::deleteCacheData($cellID);
                        throw new PHPExcel_Exception('Cell entry ' . $cellID . ' no longer exists in Wincache');
                    }
                    if (!wincache_ucache_add($newCachePrefix . $cellID . '.cache', $obj, $this->cacheTime)) {
                        $this->__destruct();
                        throw new PHPExcel_Exception('Failed to store cell ' . $cellID . ' in Wincache');
                    }
                }
            }
            $this->cachePrefix = $newCachePrefix;
        }

        /**
         * Clear the cell collection and disconnect from our parent
         * @return    void
         */
        public function unsetWorksheetCells() {
            if (!is_null($this->currentObject)) {
                $this->currentObject->detach();
                $this->currentObject = $this->currentObjectID = null;
            }
            //    Flush the WinCache cache
            $this->__destruct();
            $this->cellCache = [];
            //    detach ourself from the worksheet, so that it can then delete this object successfully
            $this->parent = null;
        }
    }
